丁羟推进剂药浆流平性能实验与模拟

Experiment and Simulation of Leveling Performance of Hydroxy-Terminated Polybutadiene Propellant Slurry

为研究表观黏度及屈服应力对丁羟推进剂药浆流平性的影响,文中对丁羟推进剂药浆进行了流平性实验,并提出滞止角的概念来表征药浆的流平性,得出药浆屈服应力对滞止角的影响规律。同时采用Carreau黏度模型模拟了药浆流平过程并与实验结果进行了对比,并通过计算软件Flow3D定量表征了丁羟推进剂药浆的表观黏度、屈服应力单变量对流平性的影响。结果表明,丁羟推进剂药浆的流动角度与药浆流平时间的对数满足线性关系;不同时刻药浆流动角度的数值模拟与实验结果误差在5%以内,内侧流到终点的时间相差小于10%,验证了Carreau黏度模型求解药浆流平过程的可行性。丁羟推进剂药浆的表观黏度是影响流平速度的主要参数,当表观黏度由400 Pa·s增大到1000 Pa·s时,药浆流平所需时间由277s延长到871s;屈服应力决定了药浆流平结束时滞止角的大小,当屈服应力由60Pa增大到120Pa时,滞止角由8.69°增大到14.98°,相应增加了72.4%。

Viscosity and yield stress have an important influence on the leveling performance of hydroxy-terminated polybutadiene(HTPB)propellant slurry.In this study,through the leveling experiment of propellant slurry,it is concluded that slurry viscosity is the key criterion affecting leveling time.And the influence law of yield stress on stagnation angle was studied.At the same time,the leveling process of slurry was simulated by Carreau viscosity model and compared with the experimental results,and the effects of viscosity and yield stress on leveling performance were quantitatively characterized by computational fluid dynamics software computational fluid dynamics(CFD).The results show that the error between the numerical simulation and experimental results of slurry flow angle at different leveling time is less than 5%,which verifies the feasibility of Carreau viscosity model to solve the slurry leveling process.The relationship between the flow angle of the studied slurry in the leveling tester and the natural logarithm of the slurry leveling time is close to linear.Univariate analysis was carried out on the viscosity and yield stress of the slurry.When the viscosity increases from 400 Pa·s to 1000 Pa·s,the time required for slurry leveling is increased from 277 s to 871 s.When the yield stress is increased from 60 Pa to 120 Pa,the corresponding stagnation angle is increased from 8.69°to 14.98°,with a corresponding increase of 72.4%.